1. Field of the Invention
The invention relates to treatment of ores, particularly phosphate ore. More particularly, it relates to modifying the process of formation of slimes therein. Still more particularly, the invention relates to the modification of slime formation in a phosphate ore matrix by adding thereto an electrolyte solution prior to significant slime generation, e.g., prior to washing or classification.
2. Description of the Prior Art
Phosphate matrix, large deposits of which are found in central Florida, is found largely in deposits averaging about 20 feet in thickness, beginning about 15 feet below the surface. Thus the matrix is mined by open pit methods.
The matrix comprises clay, silica sand and phosphate. The clay is predominantly -5 microns in size. The matrix, after being taken from the ground by draglines, is dropped into an open pit dug out of the surface of the overburden and is transported to the plant by known means.
During hydraulic slurrying, transport, and subsequent washing, screening and classification, extremely finely divided material originally in the matrix remains in suspension in the water, producing the common phosphate slime. There have been many attempts to coagulate slimes and to salvage the phosphate values present therein. Such attempts include mechanical methods (e.g., U.S. Pat. No. 3,008,575) and chemical methods (e.g., U.S. Pat. No. 3,314,537). These methods, though, have operated on the slimes after it is formed. The method of this invention effectively modifies the formation of the slimes, leading to their rapid coagulation.